> I don't think it's a problem with the underlying argument - surely the
> main point is that 'food miles' is a single-factor measure when a
> multiple-factor measure is called for, or at least, if carbon
> emissions is your interest, make that your single measure. How is the
> source of electricity not relevant?
Certainly it matters, and I agree that food-miles are a over-simplified metric. My problem is that if the critique is on target -- I recall similar ones, though I haven't read the report itself -- it sounds like they were gaming the analysis for a bit of national advocacy instead of an objective examination of food miles. For example, overland transportation is well understood to be much more carbon intensive than sea freight. Why take their hydroelectric production vs. coal into account and leave that out? And does Britain really have to go to the antipodes for grass fed meat? There's nothing in Britain, and nothing in between? If it's worthwhile in carbon terms to get it from NZ, surely it's even better to get it from Iceland. They're big on non-combustion energy, too.
There are better ways to illustrate the point. For example, supposedly it takes less carbon to get wine to the eastern US from Europe than overland from California (where so many fruits and veggies get shipped from) due to those disparities in land vs. sea transport.
-- Andy